1. Field of the Invention
The present invention relates to a positive-type photosensitive resin composition, a cured film, a protecting film, an insulating film, a semiconductor device, and a display device using the films.
2. Description of Related Art
A polyimide resin having excellent heat resistance, superior electrical and mechanical properties, and the like has generally been used as a surface protecting film and an interlayer dielectric in semiconductor devices. In recent years, a polybenzoxazole resin which is regarded as having good moisture resistance reliability due to the absence of a carbonyl group that has high polarity and is derived from an imide ring has been used, and a photosensitive resin composition which can simplify a part of a relief pattern formation process due to photosensitivity is under development.
Nowadays, in order to further improve the photosensitive resins in terms of safety, a positive-type photosensitive resin composition which comprises a polybenzoxazole precursor which can be developed by an alkaline aqueous solution and a diazoquinone compound as a sensitizer has been developed (see JP-A-56-27140). Production of a relief pattern will now be described by way of a development mechanism of the positive-type photosensitive resin composition. Irradiation of (exposure to) actinic rays through a mask using a photolithographic device such as a stepper produces exposed areas and unexposed areas in a coated film on a wafer. The diazoquinone compound in the unexposed areas is insoluble in an alkaline aqueous solution, and provided with further resistance to the alkaline aqueous solution as a result of the interaction with the resin. On the other hand, the diazoquinone compound which is present in the exposed areas chemically changes by the action of the actinic rays and becomes soluble in an alkaline aqueous solution, thereby promoting dissolution of the resin. A relief pattern consisting only of the unexposed areas can be prepared by dissolving and removing the exposed area utilizing the solubility difference of the exposed areas and unexposed areas.
However, since the cured film produced from the photosensitive resin composition disclosed in JP-A-56-27140 has only poor adhesion to a substrate such as a silicon wafer, the film causes problems such as peeling after high temperature and high humidity treatment.